Thursday 30 January 2020

Fusion Energy

The fundamental currency of our universe is energy. It lights our homes, grows our food, powers our computers. We can get it lots of ways: Burning fossil fuels, splitting atoms, or sunlight striking photovoltaics. But there's a downside to everything.

Fossil fuels are extremely toxic, Nuclear waste is... well, nuclear waste, Solar and wind aren’t always reliable. Hydrothermal and hydroelectric aren’t widely accessible. And we'll eventually deplete our oil reserves. So Around the world people are working on fusion energy, which might be the safe, efficient, reliable, clean energy source that could save our planet.

This may come as a surprise to some, but fusion is not some futuristic, sci-fi idea, it’s real. It’s happening. You’ve seen it. Fusion energy exists every time we go out in the day and look at the sun, we see a big ball of burning hydrogen gas...If you go out at night and look at the stars, those are also billions and billions, to quote Carl Sagan “of burning plasma engines, fusion engines”.


Fusion is the process of two light atoms, like hydrogen, being forced together due to immense heat and pressure to form a heavier atom, like helium. When this merger happens, energy is released, which creates heat and light. Fusion is the energy that makes life possible on our planet (you know how). And many think fusion will power our cities of the future.

Unlike fossil fuels, Nuclear fusion doesn’t release toxins and polluting greenhouse gasses like carbon dioxide. The byproduct of fusion is helium, an inert, non toxic gas. The fuel is made of two hydrogen atoms that can be pulled from our abundant supply of seawater. And yes, fusion does produce radioactive byproducts, but the half-life of that waste is much shorter than in a fission reactor.

We currently have the technology to heat up hydrogen atoms to well beyond the temperature of the sun, to a point where fusion can occur. We have the technology to keep that superheated plasma (gas that has been energized to the point that electrons break free from the nucleus an travel with them) in place long enough for fusion to occur. We know we can turn heat into electricity and currently have the infrastructure to put that electricity onto the grid. So what are we waiting for?


Well, it all comes down to Q. In the world of fusion, Q represents “energy gain.” It is the ratio of the nuclear power generated to the power required to maintain the plasma in the steady state. And right now scientists are finding ways to build a fusion reactor which could produce ten times the energy that’s putting in. That’s the goal for ITER (International Thermonuclear Experimental Reactor), the largest scale fusion experiment on the planet that’s been in the works for decades.

ITER, which means ‘the way’ in Latin and is a major international fusion collaboration that’s been in progress since 1985. China, the EU, India, Japan, South Korea, Russia, and the U.S. are all contributing members who have agreed to fund ITER’s goal of producing fusion energy that could power our world. It uses a magnetic field ( produced by superconducting electromagnets cooled with liquid helium) to squeeze a plasma in a doughnut shaped chamber where the reactions take place. The small scale model of ITER looks like this


But, ITER is an experiment only to demonstrate that fusion can produce a net energy gain. As big and expensive as it is, will not power anyone's home. If it’s successful, than a power station called DEMO will be built, aiming to put fusion electricity onto the grid somewhere between 2030 and 2050. Or, maybe even a little after that. Which is one of the complaints about the world of fusion so far; it takes time.

Government projects aren’t the only way to achieve fusion. Private companies are also getting in on the world of fusion and they’re not waiting around for ITER to prove successful. For example MIT, recently teamed up with a private company on a plan that they think could lead to an operational fusion power plant within the next 15 years.

There are fusion experiments currently being carried out all over the world and the computer models have already proved that the science works. People want it, governments wants it, private industry wants it and well...the environment wants it. It just needs to be tested, built, made scalable, approved and installed.

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